Reported Adverse Drug Reaction Cases
- Martin, K et al. Neuropathy associated with leflunomide: a case series. Ann Rheum Dis 2005; 64: 649-50.
Leflunomide and peripheral neuropathy
Leflunomide (Indian Brands Arava, Cleft, Lefno, Lefra and Lefumide) is a disease modifying anti-rheumatic prodrug (DMARD) with immunosuppressive properties. It has been available in Australia since 2000 for the treatment of active rheumatoid arthritis.
To date, ADRAC has received 659 reports in association with leflunomide, 30 of which described neuropathy or peripheral neuropathy. Leflunomide was the sole suspected drug in 24 of these cases. Ages ranged from 33 to 90 years. The daily dose of leflunomide was 20 mg in 24 cases, 10 mg in 1, 30 mg in 1, and not stated in the remaining cases. The time to onset (n=21) ranged from 2 weeks to 20 months.
Most reports described insidious onset of bilateral sensory changes such as numbness, hypoaesthesia, paraesthesia, or painful burning sensations affecting the feet and (in a few cases) the hands. Clinical findings variously included reduced sensation to light touch and pin prick, decreased vibration sense distally, and in one case 'foot drop' was noted. Decreased or absent tendon reflexes were also noted in some cases.
Nine reports included the results of nerve conduction studies which supported a diagnosis of significant length-dependent sensory or sensorimotor neuropathy. Symptoms persisted and became worse with continued use of leflunomide in several cases.
Recovery was documented after withdrawal of leflunomide in 6 patients, 3 of whom were treated with 'cholestyramine washout' (which reduces the elimination half-life of the active metabolite of leflunomide from more than one week to about one day). At the time of reporting, 15 patients had not recovered and the outcome was unknown for the remaining cases.
The cases reported to ADRAC are similar to those recently described by Martin et al.1 The temporal association of leflunomide with peripheral neuropathy and recovery on dechallenge suggest a causal relationship. The clinical features resemble the sensory peripheral neuropathy attributable to the vasculitic component of rheumatoid disease itself. Accordingly, the association may be difficult to recognise but prescribers should consider the possible role of leflunomide in patients who complain of sensory problems in the feet because in such cases the condition is potentially reversible if the drug is ceased.
Australian Adverse Drug Reactions Bulletin, Volume 5, Number 5, October 2006